Flask inverter



Dec. 5, 1967 J. E. ANDERSON 3,356,230

FLASK INVERTER Filed Aug. 26, 1965 3 Sheets-Sheet l 66 So lax 6 126/20 INVENTOR. 136 JACK E. ANDERSON dmz hivdw A T TORNEVS Dec. 5, 1967 J. E. ANDERSON 3,356,230

FLASK INVERTER Filed Aug. 26, 1965 3 Sheets-Sheet 2 INVENTOR. JACK E. ANDERSON A T TORNE VS Dec. 5, 1967 J. E. ANDERSON 3,35 ,230

FLASK' INVERTER Filed Aug. 26, 1965 3 Sheets-Sheet INVENTOR.

JACK E. ANDERSON A T TORNEVS United States Patent 3,356,230 FLASK INVERTER Jack E. Anderson, Birmingham, Micl1., assignor to Mil- Fab-Co., Incorporated, Detroit, Mich., a corporation of Michigan Filed Aug. 26, 1965, Ser. No. 482,688 17 Claims. (Cl. 214-1) This invention relates to a flask inverter, and more particularly to apparatus and a method for inverting flasks of the type commonly used in foundries for the production of castings from molten metals.

In the process of producing castings from molten metals, said molds are frequently employed. The making of sand molds usually involves the tamping of sand within a flask around a pattern. The pattern is usually placed on a base plate and is surrounded by a flask which is also placed on the base plate. After the flask is filled with the molding sand and tamped into place, a second plate is usually placed over the upper end of the flask, the two plates firmly clamped on the flask and the flask is inverted so as to permit removal of the pattern. With relatively small flasks, the job of inverting the same is a simple one. However, in the case of flasks weighing as much as five or ten tons, when filled with molding sand, the job of inverting the flask is a diflicult one, to say the least. The problems involved with the inverting of such large flasks stem not only from the tremendous mass that has to be turned over but also from the fact that such mass must be turned over or inverted carefully and without substantial jarring, so as to prevent a change in shape of the mold cavity produced by the pattern. In this connection it is also important that the flask be designed and. gripped so as to produce a minimum of distortion or deflection of the side walls thereof when it is lifted in any fashion, such as is necessary when the flask is to be inverted.

The primary object of the present invention is to provide apparatus and a method for inverting a relatively large flask without adversely affecting the flask nor a sand mold provided therein.

Another object of the invention is to assure a smooth transition of the flask from its initial position to its inverted position.

A further object of the invention is to provide a method and apparatus for inverting a flask by lifting one side of the flask and supporting the opposite side on a carriage which rolls along a supporting surface during the inverting operation.

A further object of the invention is to restrict travel of the side of the flask which is lifted to the vertical direction in order to avoid swinging motion of that side which could result if it traveled horizontally,

Another object of the invention is to support one side of the flask with a rolling carriage and pivot that side about the carriage in turning the flask over so as to minimize the risk of incurring shocks in transferring the weight of the flask to the carriage and then back to the original supporting surface.

Still another object of the invention is to provide mechanism for assuring that upon lowering the side of the flask which is first lifted, the flask will continue turning predominantly in the same direction until it is inverted and returned to its supporting surface.

In the drawings:

FIG. 1 is a perspective view of a flask after it has been raised to a generally vertical position with the method and apparatus of the invention.

FIGS. 2 through 8 are a series of views showing progressive positions of a flask while it is being inverted, using the method and apparatus of the invention.

FIG. 9 shows an arm for pivoting one side of the flask about a carriage in different positions while the flask is being inverted.

FIG. 10 is a vertical sectional view taken through the middle of the carriage.

FIG. 11 is a sectional view showing a post assembly and the manner in which it is clamped to the cross beam of the carriage.

Apparatus for inverting a flask according to the invention includes a carriage 20 (FIG. 1) and a hoist 22 attached to flask assembly 24 respectively at opposite sides thereof. Flask assembly 24 includes two flasks 26 and 23 secured together by clamps 30 and 32. The ends of flask assembly 24 are closed by plate assemblies 34 and 36 which are secured, respectively, to flasks 26 and 28 by clamps 38, 40, 42 and 44. Additional clamps are used on the other sides of the flask assembly but are not visible in FIG. 1. The clamps engage flanges 46- at the ends of the individual flasks 26, 28 and also at the open ends of the plate assemblies 34 and 36. Since the flasks and plate assemblies are conventional, further details of their construction will not be described.

Hoist 22 includes a sling 48 having arms 50 and 52 each connected at one end to plate 54 and connected at the other end to tubes 56 which are secured to flask 26. Tubes 56 serve as anchors for sling 48. The hook 58 of a double-sheave pulley 60 grasps plate 54, the pulley 60 being suspended from an overhead hoisting mechanism (not shown) by means of cables 62. The upper end of the hoist which includes the cable Winding drum is conventional and not illustrated.

At the bottom of flask assembly 24 (as viewed in FIG. 1) tubes 64, which are attached to flasks 26 and 28-, are secured by bolts 66 to plates 68, one at each end of the flask assembly adjacent the lower edge thereof as viewed in FIG. 1. The tubes 64 serve as anchors for the plates. The plates 68 are components of carriage 20 which also includes two pivot arms 70 and 72. Arms 70 and 72 are shiftably connected to plates 68 by means of two pins 74 and 76 which are secured to each plate 68 and project freely through camming slots 78 and 80 in the pivot arms. A locking finger 82 is pivotally connected to each arm 70, 72 by a pin 84.

Arms 70 and 72 are axially aligned on carriage 20 and are spaced apart a distance corresponding generally to the length of the flask assembly such that they may be attached via plates 68 to the ends of the flask assembly adjacent one edge thereof. The arms are pivotally connected to post assemblies 86 and 88 by bolts 90 and 92. Post assemblies 86, 88 rest on and are clamped to an I-beam 94, which is the cross beam of carriage 20 that extends between its trolleys 96 and 98. Post assemblies 86, 88 are adjustable lengthwise of beam 94.

The two trolleys 96, 98 are identical, and each includes a horizontal beam 100 suspended by brackets 102 and 104 from horizontal plates 106 and 108 located, respectively, over wheels 110 and 112. Plates 186 and 168 have depending forks 114 and 116 through which the wheel axles 113 and 120 extend and are secured by nuts 122 and 124. A cross brace 126 is secured at its ends to vertical plates 128, 130 anchored by bases 132, 134 which are bolted to horizontal plates 106, 108. Beam 100, brackets 102, 104 and cross brace 126 form a box frame in which the end of cross beam 94 is received. Beam 94 rests on a pad 136 which in turn rests on beam 100 of wheel assembly 96. Pad 136 is retained by sleeves 142, 144 for 'vertical movement on vertical rods 138 and 140. As will be described further, flask assembly 24 is lifted by means of hoist 22, but it is desirable to have wheels 110 and 112 remain on the supporting surface on which they ride. Cross beam 94 and pad 136 are permitted to move vertically on rods 138 and 140 should the flask assembly be lifted a little too far before it is lowered again to the supporting surface.

As shown in FIGS. 10 and 11, sleeves 142 and 144 encircle rods 138 and 140 and are secured to pad 136 at their bottom ends. There is a clearance between the top ends of sleeves 142, 144 and the cross brace 126 which accommodates vertical movement of the sleeves on the rods. The top flange 95 of cross beam 94 (FIG. 11) is received between an upper plate 146 and two lower plates 148, 150 which are drawn toward the upper plate by means of bolts 152 and nuts 154 to clamp each post assembly 86 to the cross beam. Upper plate 146 is the base of the post assembly and spaced plates 156 which receive pivot arm 70 between them are supported on plate 146 and are held upright by gussets 158.

The method of inverting a flask according to the invention is illustrated by FIGS. 2 through 8, starting in FIG. 2 with a flask or flask assembly 24 lying horizontally on a supporting surface 170. Hoist 22 is attached to the flask at one upright side 172 thereof and arriage 20 is attached to the flask at its opposite upright side 174. The wheels 110, 112 of carriage 20 contact surface 170 and preferably ride on tracks forming a part of that surface. Pivot arms 70, 72 of the carriage initialy extend downward and to the left from their pivot pins 90. Pin 74, which is fixed relative to the flask, engages the top end of camming slot 78 in arm 70 and pin 76, likewise fixed, engages the bottom end of camrning slot 89. There are identical pins, arms, and wheel assemblies at the back side of flask 24 as has ben explained in connection with FIG. 1.

Side 172 of the flask is lifted straight upward by operation of hoist 22 to raise pulley 60. Side 174 of the flask is supported by carriage 20 while side 172 is lifted. Due to the engagement of pins 74, 76 with arm 70 at the top and bottom ends of slots 78 and 80, respectively, flask 24 is rigidly connected to arm 70 such that its right side 174 swings upward with arm 70 about point 90 as its left side 172 travels vertically.

As flask 24 is lifted, it turns clockwise (FIGS. 3 and 4), carriage 20 moves under flask 24 and hoist 22 in the direction of the arrow in FIG. 3 with its wheels 110 and 112 rolling along surface 170. It may be seen by comparison of FIGS. 2, 3 and 4 that arm 70 and flask side 174 pivot about point 90 during this upward turning movement of the flask; that is, side 172 moves upward while side 174 is drawn under it by means of carriage 20 rolling horizontally along surface 170. Flask 24 is turned upwardly to the position shown in FIG. 4 simply by lifting with hoist 22.

Flask 24 is lowered from its position in FIG. 4 to continue turning it in the same direction while returning it to surface 170 in an inverted position. Four stages of this downward turning movement are shown in FIGS. 5 through 8. After pivot point 20 passes under and slightly beyond the center of gravity of flask 24, it is desirable to shift arm 70 relative to the flask to assure that the flask will continue turning in the same direction (clockwise, as viewed in the drawings) where the hoist is lowered. This shifting motion involves a slight reverse turning movement of flask 24 which will be described more fully in connection with FIG. 9, and it will suflice at present to note that pins 74 and 76 move to the opposite ends of camming slots 78 and 80 during the initial stage of the lowering of the flask. With the latter pins engaging the opposite endsof the camming slots, flask 24 is again rigidly connected to arm 70, now in a shifted position (FIG. 5), and side 174 continues to pivot with arm 70 about point 90 while side 172 is lowered toward supporting surface 170 (FIGS. 6 and 7). Carriage 20 continues rolling in the same direction along surface 170 until flask 24 again rests on surface 170.

Reviewing FIGS. 2 through 8, carriage 20 starts on one side of flask 24 and is shifted to the other side of the flask (FIG. 8). The carriage moves from right to left (-with reference to the drawings), throughout the lifting and lowering of the flask. Side 172 of the flask travels wholly upward while it is being lifted, and travels wholly downward while it is being lowered, although it also goes through a turning motion while it travels up and down. Side 172 returns to approximately the same place on surface 170 where it started. Side 174 pivots about pin 90 as it goes from one side of hoist 22 to the opposite side of hoist 22.

The operation of pivot arm 70 and the couple formed by pins 74 and 76 as arm 70 pivots clockwise about pin 90 is illustrated by FIG. 9. Although only the pivotal component of the motion of arm 70 is indicated by the changing positions A, B, C, D and E of the arm in FIG. 9, it should be noted that all of the structure shown in FIG. 9 moves horizontally while the flask is being inverted. The sequence starts with arm 70 extending downward and to the left from pivot pin 90. As previously mentioned, pin 74 initially engages arm 70 at the top of camming slot 78, and pin 76 initially engages arm 70 at the bottom end of camming slot 80. One end 81 of locking finger 82 projects across slot 78 and its other end 83 abutts against stop 85. Tube 64 is initially in a horizontal position corresponding to the horizontal position of flask 24 in FIG. 2, and its various positions corresponding to those of arm 70 are also denoted A, B, C, D and B.

When arm 70 moves to position B there is no change in the positions of pins 74 and 76 relative to the camming slots 78 and 80. Between positions B and C, however, pin 74 travels along slot 78 and in doing so contacts end 81 of locking finger 82, which then rides up over pin 74. Pin 76 has not moved from its initial position in slot by the time arm 70 reaches position C.

The movement of pin 74 along slot 78 begins just after pin 74 reaches a position directly above pin 76; i.e., when pins 74 and 76 become aligned vertically (assuming a vertical lifting force). Since pins 74 and 76 are aligned axially of flask 24, they become vertically aligned when flask 24 reaches a vertical position. From this vertical position to and slightly beyond position C, flask 24 continues to turn clockwise but at a slower rate than arm 70 is turning, and as a result of this differential, pin 74 rides along the bottom edge of slot 78 towards corner 87. Pin 76 is the pivot point about which this differential relative movement of arm 70 and flask 24 takes place. During this phase, pin 74 moves beyond finger 82 which then drops behind pin 74 preventing it from returning along slot 78.

The main pivot pin passes under and beyond the center of gravity of flask 24 before arm 70 reaches its vertical position C because of the tilted relation of the flask to the pivot arm. Hoist 22 continues to lift the flask until pin 76 and pin 90 become vertically aligned, and this condition occurs just beyond position C. At this stage, pin 78 has cleared corner 87 of camming slot 78 and is free to move down straight leg 89 of that slot. Consequently lowering of hoist 22 begins as soon as pin 74 clears corner 87 which happens when pin 76 is directly above pin 90.

While flask 24 is initially being lowered, pins 74 and 76 both ride downward to the opposite ends of their respective camming slots 78 and 80 (see position D).

It may be noted by comparing positions C and D in FIG. 9 that tube 64 and flask 24 turn counterclockwise relative to arm 70 during this phase of the overall clockwise turning motion. This brief counterclockwise turning motion is incident to the shifting of flask 24 relative to arm 70 to assure that the flask will continue to turn clockwise when it is lowered, rather than returning in the counterclockwise direction to its starting position. While traveling downward in slot 80, pin 76 exerts a camming force against edge of that slot which continues to push carriage 20 to the left even though flask 24 is turning counterclockwise at this time.

From the above description it will be apparent that the arcuate portion ofslot 78 is struck about the end 80a of inclined siot 80. Likewise the end 80b of slot 80 and the end 78b of the straight portion 89 of slot 78 are spaced apart a distance corresponding to the spacing of pins 74, 76. The tilting of the flask in the proper direction when the hoist is lowered after position C is reached is assured by the relationship between the straight portion 89 of slot 78 and inclined slot 80. In the illustrated embodiment it will be observed that the tube 56 to which the hoist is connected is offset to one side of the centerline of the flask while plate 68 to which arm 70 is connected is symmetrical to the horizontal centerline of the flask. This offset relationship between the point of application of the lifting force on the flask and the pivotal connection between the flask and arm 70* is not essential and is shown only by way of illustration. The assurance that the flask will continue to rotate in the proper direction for inverting after it has been hoisted to the high point and then lowered results from the fact that as pins 74, 76 start moving downwardly in their respective slots arm 70 is forcibly pivoted in the clockwise direction as viewed in FIG. 9. The center of gravity of flask 24 remains on the right of pin 90 (FIG. 2) while it is shifted during the period between positions C and D.

Between positions D and E, pins 74 and 76 remain engaged with the opposite ends 7812 and 80b of slots 78 and 80, providing a rigid coupling between tube 64 and arm 70. In position E, tube 64 has returned to a horizontal position, and flask 24 has returned to surface 170 but now flask 24 is inverted compared to position A.

The flask is inverted by the method and apparatus of the invention smoothly and without any substantial bumping or jarring. The inverting operation can be accomplished relatively quickly and with only minimal supervision. The investment in equipment required to practice the invention is no greater than has been required for known types of apparatus, and a definite improvement in results is obtained. It will also be noted that the manner in which the flask is engaged by the inverting mechanism at tubes 56, 64 reduces to a minimum the tendency of the flask to distort.

I claim:

1. A flask inverter comprising a carriage having floor engaging wheel members, a pair of spaced apart arms pivotally supported in axially aligned relation on the carriage, means on said arms for securely attaching the arms to a flask to be inverted and lying on a ground surface adjacent the carriage, said arms being spaced apart on said carriage a distance corresponding generally to the length of the flask so that the arms may be secured to the flask adjacent one edge thereof, and hoist means adapted to be connected with the flask adjacent the opposite edge thereof for raising and lowering said last mentioned opposite edge to thereby pivot the flask in a vertical plane on said carriage from a position at one side of the carriage to an inverted position on the other side of the carriage while the carriage rolls from one side of the hoist means to the other side thereof.

2. The flask inverter of claim 1 wherein said carriage includes a pair of trolleys on which said wheels are journalled and a cross beam interconnecting said trolleys, said arms being pivotally supported by said cross beam and said cross beam being capable of shifting vertically on said trolleys within a predetermined range of vertical travel to accommodate vertical overtravel of the hoist means.

3. The flask inverter called for in claim 1 wherein each said arm has a free end portion remote from its pivot support portion, a plate at the free end portion of each arm, means for fixedly connecting each plate with said opposite ends of the flask and means interconnecting each plate with the free end portion of the arms such that when the flask has been turned upward in one direction to a generally upright position and operation of the hoist means is reversed to lower said opposite edge of the flask said plate causes the arm to continue pivoting in the same direction.

4. The combination called for in claim 3 wherein said last-mentioned means comprises a pair of cam slots, 21 pair of pins on each plate engaging and movable in said cam slots upon raising and lowering of the hoist means and a latch on each plate for preventing one of said pins to reverse its direction of travel in its associated slot when the operation of the hoist means is reversed after the arms are pivoted to a generally upright position.

5. The combination called for in claim '1 including shiftable means connecting each said arm to said flask such that after the flask has turned upward in one direction to a topmost position wherein further elevation of said opposite edge of the flask by said hoist would tend to bodily lift the carriage and operation of the hoist means is reversed to lower said opposite edge of the flask, said shiftable means shifts on said arm so as to continue pivoting said arm in the same direction.

6. The combination called for in claim 5, wherein each said arm has a pair of camming slots therein and said shiftable means comprises a plate having pins passing freely through said camming slots and movable therein to allow the shifting of said plate.

7. The combination called for in claim 6, wherein said pins on said plate are vertically spaced generally one above the other when said flask is in said topmost position, one of said cam slots in said arm, when the arm is in a generally vertical position, having a portion extending generally vertically, and the other cam slot extending downwardly and in the direction which the flask is intended to travel such that upon lowering of the flask by said hoist means the pins shift downwardly in said slots to briefly turn the flask in the reverse of its predominant turning motion while said arms continue rotating in the flask inverting direction.

8. The combination called for in claim 7 wherein said first mentioned slot has an arcuate portion extending from the upper end thereof downwardly and laterally in the direction of the lower end of the other cam slot when the flask is in said topmost position.

9. The combination called for in claim 8 wherein the pin associated with said one slot moves from said lower end of said arcuate portion to the upper end thereof when said opposite edge of the flask is pivoted to a generally upright position and including a latch for constricting the pin associated with said one slot to follow the generally vertically extending portion thereof when the operation of the hoist means is reversed with the flask in its uppermost position.

10. In combination a supporting surface, a flask resting on said supporting surface, said flask having a pair of end walls and a pair of side walls rigidly secured together, said flask also having means thereon closing the top and bottom faces of the flask, anchor means on each end wall of the flask adjacent the opposite vertical edges thereof, a carriage adjacent one side of the flask and having wheels thereon supporting the carriage for rolling movement on said supporting surface, said carriage having a pair of arms pivotally supported at pivots thereon in axially aligned relation, one adjacent each end wall of the flask, means connecting the free end of each said arm with the anchor means on the flask adjacent the carriage, and an overhead hoist mechanism connected with the anchor means remote from the carriage, the means connecting said arms with the anchor means being arranged to pivot the arms upwardly on the carriage in respect to raising of the hoist mechanism whereby when the hoist mechanism is raised and lowered said flask is pivoted about said pivots as an axis.

11. A method of inverting a casting flask initially lying horizontally on a supporting surface comprising (a) attaching a hoist and a carriage to said flask respectively adjacent first and second opposite upright sides of said flask, said carriage having wheels adapted to roll along said supporting surface,

(b) lifting said first side of said flask with said hoist while supporting said flask with said carriage at said second side and thereby turning said flask to a generally vertical position on said carriage by rolling said wheels along said supporting surface in a horizontal direction passing under said hoist,

(c) lowering said first side of said flask with said hoist while supporting said flask with said carriage at said second side thereof and thereby continuing to turn said flask at least predominantly in the same direction by rolling said wheels in said horizontal direction, thus returning said flask to the supporting surface in an inverted horizontal position.

12. The method of claim 11 further including pivoting said second side of said flask about said carriage while inverting said flask.

13. The method of claim 12 wherein said pivoting is accomplished with an arm pivotally connected to said carriage and shiftably connected to said second side of said flask.

14. The method of claim '13 further including shifting said second side of said flask relative to said arm just after the pivot point of said arm passes under the center of gravity of said flask to assure continued pivotal movement of said arm in the same direction while said flask is lowered.

15. The method of claim 14 wherein during said shifting of said flask relative to said arm said flask turns briefly in the reverse of its predominant turning motion but the center of gravity of said flask remains on the side of said pivot point opposite the side where it started.

16. A method of inverting a casting flask initially lying horizontally on a supporting surface and having a sand mold therein comprising (a) attaching a hoist and wheels to said flask respectively adjacent to first and second opposite sides of 35 (b) lifting said first side of said flask with said hoist while moving said second side thereof on said wheels under said first side by rolling said whecls along said supporting surface in a horizontal direction passing under said hoist, thereby turning said flask to a generally vertical position on said wheels,

(0) and lowering said first side of said flask while further moving said second side thereof in said direction by continuing to roll said wheels along the supporting surface in said direction, thereby turning the flask over and returning the same to the supporting surface in an inverted horizontal position.

17. The combination called for in claim 1 wherein said scans for attaching the arms to the flask include means for tilting the flask slightly when said opposite edge is lowered from its topmost position by reversing the direction of operation of the hoist means to assure the continued pivotal movement of the flask in the inverting direction upon continued lowering of said opposite edge of the flask.

References (Iited UNITED STATES PATENTS 838,908 12/1906 Schaum 22-33 951,953 3/1910 Lewis 22-33 2,443,307 6/1948 De Cuir 2l4-2.5 X 3,083,840 5/1963 Gibbs 214-1 3,197,826 8/1965 Sanchez 214-1 FOREIGN PATENTS 649,211 8/1937 Germany.

GERALD M. FORLENZA, Primary Examiner.

G. F. ABRAHAM, Assistant Examiner. 

1. A FLASK INVERTER COMPRISING A CARRIAGE HAVING FLOOR ENGAGING WHEELS MEMBERS, A PAIR OF SPACED APART ARMS PIVOTALLY SUPPORTED IN AXIALLY ALIGNED RELATION ON THE CARRIAGE, MEANS ON SAID ARMS FOR SECURELY ATTACHING THE ARMS TO A FLASK TO BE INVERTED AND LYING ON A GROUND SURFACE ADJACENT THE CARRIAGE, SAID ARMS BEING SPACED APART ON SAID CARRIAGE A DISTANCE CORRESPONDING GENERALLY TO THE LENGTH OF THE FLASK SO THAT THE ARMS MAY BE SECURED TO THE FLASK ADJACENT ONE EDGE THEREOF, AND HOIST MEANS ADAPTED TO BE CONNECTED WITH THE FLASK ADJACENT THE OPPOSITE EDGE THEREOF FOR RAISING AND LOWERING SAID LAST MENTIONED OPPOSITE EDGE TO THEREBY PIVOT THE FLASK IN A VERTICAL PLANE ON SAID CARRIAGE FROM A POSITION AT ONE SIDE OF THE CARRIAGE TO AN INVERTED POSITION ON THE OTHER SIDE OF THE CARRIAGE WHILE THE CARRIAGE ROLLS FROM ONE SIDE OF THE HOIST MEANS TO THE OTHER SIDE THEREOF. 